HPTuners instant MPG
Thread Starter
On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
HPTuners instant MPG Hey guys, I've been trying to set up an instant MPG PID/average histogram using a formula that seems to be successful for a lot of people, but I can't get it to work right for the life of me. It's throwing wildly high figures, even with dfco off and the histogram set to ignore TPS <2. I don't know if I'm screwing something up, or the formula was somehow broken in newer updates, anyways here it is "[MPH]/(([Injector Flow Rate]*0.132276)*[InjectorPulse Width]*[RPM]*8/(6175*(((([IAT]+[ECT])/2)+273.15)/299.8167)))" I know the last half is a fuel density compensation, but I can't make heads or tails of what's happening to calculate the fueling. I've tried playing with the units when I set the graph up, but the numbers only get further out when I match the units up, default seems to get me close, but it's nowhere near accurate. Any input is appreciated, I'm driving myself mad trying to figure this out
TECH Fanatic
Joined: Dec 2017
Posts: 1,469
Likes: 266
From: Bossier City, Louisiana
I don't wish to discourage you here with HP Tuners but most of the Android OBD II apps do this calculation with ease. With my fifteen dollar Konnwei Bluetooth OBD II or OBD Link MX + reader and an Android phone app, this is both easy and accurate for average and instantaneous fuel mileage.
Maybe not the answer you were looking for . . . my two cents.
Rick
Maybe not the answer you were looking for . . . my two cents.
Rick
Thread Starter
On The Tree
Joined: Oct 2018
Posts: 111
Likes: 2
From: Upstate New York
Yeah, I get that, I actually have one of those Bluetooth adapters, I kind of forgot they show mpg. The thing is though, I don't *really* need or want the mpg as a stand-alone figure. I was just hoping to have it mapped out by load cell with the rest of my scan more so for curiosity's sake than anything, and to see which changes affect mpg and where. Although you did give me an idea, I'm going to dig through the app a little bit and see if I can find out what inputs they're using to calculate fuel flow
